Improvement in slate-cutting machines



;c. T. BoNsALL.

slate' cutting-Machines.

Patented April 28, 1874.

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UNITED STATES PATENT OFFICE.-

GHARLES T. BONSALL, OF PHILADELPHIA, PENNSYLVANIA. y

IMPROVEMENT IN SLATE-CUTTING MACHINES.

Specification forming part of Letters Patent N o. 150,279, dated April 28, 1874 application filed February 28, 1874.'

To all whom it may concern:

Be it known that I, CHARLES T. BoNsALL, of the city and county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Slate-Cuttin g Machines; and I do hereby declarethe following to be a clear and exact description of the nature thereof sufficient to enable others skilled in the art to which my invention appertains to fully understand, make, and use the same, reference being had to the accompanying drawings making' part of this specification, in whichf 1 Figure l is a side view of the device embodying my invention. Fig. 2 is an end view thereof.

Similar letters of reference indicate corresponding parts in the two figures.

This invention consists in means for imparting rapid motions to the blade or cutter, whereby the slate will be smoothly, uniformly, and quickly cut.

Referring to the drawings, A represents a frame for supporting the various parts of the device. B represents an oscillating shaft, whose bearings are on the frame A, and to the shaft is secured the cutter or blade C, whose construction is preferably of the form to produce the well-known draw 7 cut. An arm D is secured to the shaft B, and extends therefrom in a line at or about right angles to the blade or cutter C. The lower end of this arm D carries a pin, G, (on which may be mounted a roller,) which engages with the cam-groove H of an elliptic or other shaped piece, J, secured to a rot-ary shaft, K, to which power is communicated in any suitable manner. rlhe groove H extends, at the end to which the piece J is secured to the shaft K, in a curved line concentric to the said shaft, as at a; then continues longitudinally at one side, in somewhat of a right line, toward the opposite end of the piece, as at b,- curves laterally at c; and then returns on the other side, at d, to the portion a. L represents a counterpoise which is formed with the piece J at the end to which said piece is connected to the shaft K.

The operation is as follows: When power is applied to the shaft K, the piece J receives a rotary motion, and imparts an oscillatory motion to the arm D, and thus to the shaft B, whereby a reciprocating motion is imparted to the cutter or blade C. When the pin G of the arm'D moves in the part b of the groove H, as shown in the drawings, the cutter or blade is elevated, and the slate may be laid on the. bed, which is suitably arranged in relation to the blade or cutter, yso that, on descent of the blade, the slate may be cut. The rotation of the piece J advances the groove H, so that the pin G occupies the concentric portion c of the cam-groove; and, until the end of said concentric groove is reached by the pin G, there is no motion imparted to the arm D. Consequently, the elevation or dwell 7 of the blade or cutter continues sufficiently long to properly apply the slate to the knife. The counterpoise is now uppermost, and, as soon as the pin G of the arm D clears the concentric portion c of the groove H and reaches the part d thereof, the rotation of the piece J causes the counterpoise to pass the center,

and the pin G, moving in the portion Z of the groove, causes the arm D to swing away from the shaft K, which is the axis of the piece J. The pin G now successively enters the curved portion c and longitudinal portion b, whereby the arm D again moves toward the shaft K, thus imparting an oscillating motion to the shaft B, and consequently a risin gand-fallin g motion to the blade or cutter. The passage of the counterpoise L beyond the center causes the pin G to move quickly from the portion d of the cam-groove, around the portion c, into 4the portion b, whereby, by means of the arm D, there is a rapid motion or fly imparted to the blade or cutter, a feature which is of vast importance, inasmuch as thereby the slate will be uniformly and smoothly cut. When the pin G again reaches the portion b, the blade or cutter is at its highest position, whereby a dwell thereof again occurs, so that the cut slate may be removed and another slate presented to the knife.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. The combination, with the blade or cutter C and oscillating arm D, of the piece J, formed with the cam-groove H, when constructed and operating as herein set forth.

2. The con1bination ,with the blade or cutter constructed, arranged, and operating as here- G and 1gscillating arm D, of the cam-grooved in set forth. piece J L constructed and operatin01 substantially as7 and for the purpose set foiith. CHARLES T' BONSALL' 3. The rotating piece J L with cam-groove Witnesses: a b c d, and the oscillating arm D with pin Gr, JOHN A. WIEDERSHEIM, i; in combination with blade or cutter C, when ARTHUR OBR.

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